groups-loop.php

function groups_meta_filter($query_string, $object){

  parse_str($object, $n_object);
  if( $object != 'groups' && $n_object['type'] != 'groups' )
    return $query_string;


  $args = wp_parse_args( $query_string, array(
      'action'  => false,
      'type'    => false,
      'user_id' => false,
      'page'    => 1
  ) );

  if( bp_is_user() )
      $args['user_id'] = bp_displayed_user_id();

  $args['meta_query'] = array(
    'relation' => 'AND', // Optional, defaults to "AND"
  );

  if(isset($n_object['student_level'])){
    $slq = array('relation' => 'OR');
    foreach($n_object['student_level'] as $sl){
      $slq[] = array(
        'key'     => 'e2e_student_level',
        'value'   => $sl,
        'compare' => 'LIKE'
      );
    }
    $args['meta_query'][] = $slq;
  }
  if(
    isset($n_object['year'])     ||
    isset($n_object['semester'])
  ){
    $start_date = $n_object['year'][0].'-'.$this->get_semester_ordinal($n_object['semester'][0]);
    $end_date   = $n_object['year'][1].'-'.$this->get_semester_ordinal($n_object['semester'][1]);
    $this->debug($start_date, '$start_date');
    $this->debug($end_date, '$end_date');
    $timeframe_meta_query = ['relation' => 'OR',
      [
        'key'     => 'e2e_semester_order',
        'value'   => [$start_date, $end_date],
        'compare' => 'BETWEEN'
      ]
    ];

    $args['meta_query'][] = $timeframe_meta_query;

  }
  $n_query_string = empty( $args ) ? $query_string : $args;
  $this->debug($n_query_string,'$n_query_string');
  return apply_filters( 'bp_plugin_group_querystring_filter', $n_query_string, $query_string );

}
add_filter( 'bp_ajax_querystring', 'groups_meta_filter', 60, 2 );


<?php if ( bp_has_groups( bp_ajax_querystring( http_build_query($_GET) ) ) ) : ?>
...
<?php endif; ?>